Known in the art is 5-fluorouracyl which is currently employed in oncology for non-operable forms of gastro-intestinal carcinoma, lung cancer and ovary carcinoma. (J. Amer. Chem. Soc. vol. 79, No. 16, published 1957; R. Dushinsky, E. Pleven, C. Heidelberg "The synthesis of 5-Fluoropyrimidines".
This compound, however, is highly toxic, it strongly affects the function of bone marrow and gastro-intestinal tract.
Another analog of the compound according to the present invention is 1-(.alpha.-furanidyl)-5-fluorouracyl (Ftorafur) (cf. British Pat. No. 1,168,391, Cl. C 07 d 51/30 1969). This is a low-toxic (LD.sub.50 for mice is 750 mg/kg) compound having rather high activity in respect of solid experimental tumors: sarcoma 180, Harding-Passey melanoma, Walker carcinosarcoma, alveolar carcinoma of liver. In clinics the preparation based on Ftorafur is employed for treating mammal carcinoma, rectum carcinoma, large intestine and stomach cancer. This preparation, however, inhibits hemopoiesis and causes complications on the side of the gastro-intestinal tract. Furthermore, Ftorafur, likewise fluorouracyl, lacks paramagnetic properties.